首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1011篇
  免费   51篇
  国内免费   1篇
电工技术   6篇
综合类   8篇
化学工业   411篇
金属工艺   25篇
机械仪表   8篇
建筑科学   50篇
矿业工程   2篇
能源动力   12篇
轻工业   135篇
水利工程   11篇
石油天然气   4篇
无线电   31篇
一般工业技术   152篇
冶金工业   34篇
原子能技术   2篇
自动化技术   172篇
  2024年   3篇
  2023年   9篇
  2022年   47篇
  2021年   66篇
  2020年   25篇
  2019年   28篇
  2018年   27篇
  2017年   33篇
  2016年   41篇
  2015年   37篇
  2014年   55篇
  2013年   73篇
  2012年   80篇
  2011年   68篇
  2010年   49篇
  2009年   43篇
  2008年   63篇
  2007年   40篇
  2006年   46篇
  2005年   34篇
  2004年   23篇
  2003年   19篇
  2002年   21篇
  2001年   16篇
  2000年   7篇
  1999年   15篇
  1998年   16篇
  1997年   10篇
  1996年   7篇
  1995年   6篇
  1994年   10篇
  1993年   8篇
  1992年   6篇
  1991年   8篇
  1990年   4篇
  1989年   9篇
  1986年   2篇
  1985年   3篇
  1982年   1篇
  1981年   1篇
  1980年   3篇
  1977年   1篇
排序方式: 共有1063条查询结果,搜索用时 15 毫秒
101.
Clinical proteomics aims at the development and the implementation of novel biomarkers that demonstrate a clear clinical benefit in the management of diseases. However, though the attention in the field is increasing and multiple articles on biomarker research are published, clinical implementation of these biomarkers is scarce. In this paper, we aim towards identifying the hurdles on the path towards implementation, and present one successful approach, based on capillary electrophoresis coupled with mass spectrometry. A panel of biomarkers identified and assessed using this approach, termed CKD273, has recently received a Letter‐of‐Support from the US‐Food and Drug Administration (FDA), and is now implemented in the (early) management of chronic kidney disease. Based on this experience in the process towards implementation of CKD273, issues associated with implementation and suggestions how to meet these challenges are given.  相似文献   
102.
103.
104.
The acquisition of single-tree-related information is an important task, especially in urban areas where there is an increasing interest in standing carbon stock. Therefore, an easy and robust method was developed to extract the volume, diameter at breast height (DBH) and height of single trees from point clouds of terrestrial laser scanning. For data acquisition, nine trees were scanned from several positions and the resulting high-resolution point clouds (20–60 million points) were analysed by an algorithm based on voxel structure. First, noise reduction was carried out, followed by filling of voxels inside the stem and branches through the intersection of four orthogonal viewing directions. After the elimination of erroneously generated fillings, volume was determined layer-wise for each cross section. For quality assessment, nine deciduous trees were selected, cut, weighed and analysed for wet specific gravity and carbon content in order to provide a control value. The estimated volumes agree with the control value within a range of –5.1% to +14.3%. This is also the case with DBH values; however, heights are systematically underestimated.  相似文献   
105.
106.
107.
This study deals with a numerical solution of a 2D unsteady flow of a compressible viscous fluid in a channel for low inlet airflow velocity. The unsteadiness of the flow is caused by a prescribed periodic motion of a part of the channel wall with large amplitudes, nearly closing the channel during oscillations. The channel is a simplified model of the glottal space in the human vocal tract and the flow can represent a model of airflow coming from the trachea, through the glottal region with periodically vibrating vocal folds, and to the human vocal tract.  相似文献   
108.
This study investigated the role of experience in recovery of pulmonary respiration during axonal regeneration in Lymnaea stagnalis. Pulmonary respiration occurs when snails break the water surface and open the lung orifice, the pneumostome. It was shown that axotomy of all the axons innervating the pneumostome and surrounding area prevents the occurrence of lung respiration in 69% of snails. In the remaining 31%, lung respiration persisted, indicating that peripheral components alone are capable of initiating pneumostome openings and closures. Five weeks postsurgery, all snails with previous nerve crushes showed opening of the pneumostome with normal latency after breaking the water surface. However, prevention of pulmonary respiration during the recovery period dramatically changed the recovered behavior. Thus, experience in pulmonary respiration during axonal regeneration plays a role in the recovery of this behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
109.
At NIAB, a UK based company that provides research, services and information to the agricultural and food sector, a system has been designed that helps to assess and manage the growing research programme of the company. Since the company was ‘privatised’ four years ago, research activities have increased and moved away from solely applied research to a mix of applied and more fundamental research. Being a key element of the new developed company strategy, research now plays an increasing important role in broadening the scope of the company and keeping current services competitive by driving innovation. All research at NIAB is externally funded. In this paper we report on the process to design NIAB’s performance measurement system, for which the Performance measurement system Systematic Design Approach was used. The design process was started with an elaborate structured problem analysis of the research process and its inter and extra–organisational context. Based upon this analysis, firstly a conceptual and secondly a detail design of a performance measurement system was made. To maximise the leverage from research, the system has been designed to optimise the value delivered to the funder as well as the value delivered to internal customers in the form of knowledge that drives innovation.  相似文献   
110.
The influence of an addition of either sand and/or spring-bloom algae on the efflux of nutrients from intact sediment cores from the Baltic Sea was studied in a flow-through experiment. The addition of sand significantly increased the efflux of silicon (Si) from sediment, but the algal addition did not. The effects on phosphorus (P) were not as clear, and fluxes of nitrogen (NH4 and NO2?+?3) remained relatively unaffected by the additions. The small effect of the algal addition was caused by the short time-period covered by the experiment and possibly by adsorption of released Si by the sediment. A follow-up bottle experiment showed that despite the apparently lower content of easily available Si and biogenic silica, BSi, in the sand, the sand-induced Si efflux was caused by release of Si from the sand itself, rather than by indirectly increasing the dissolution of BSi present in the sediment.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号